Sheet metal shears



y 1949. J. HART 2,469,036 I SHEET METAL SHEARS Filed Dec. 15, 1945 nvvzwro 5rd g 47% A 7' TOP/VEY Patented May 3, 1949 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to manually operated cutting tools and it has particular reference to sheet metal shears, and its principal object resides in the provision of a tool embodying features which enable its use in executing either right or left hand cuts or a spaced double cut and thus affords a single instrument capable of serving the purpose of two or more shears of conventional design.

Another object of the invention resides in the provision of sheet metal shears in which a double arrangement of cutting blades is provided, each capable of independent operation, yet designed for unitary function by which a pair of parallel cuts can be accomplished as in preparation of the work for dove-tailing operations, and the like, employed in the joining of sheet metal conduits at angles and providing angular joints in pipe.

Broadly, the invention seeks to comprehend the provision of an inexpensive, simple tool whereby much time and labor can be saved by providing the mechanic with an instrument in which the utility features of several tools are embodied in one and thus save the expense of several tools and the time required in the changing from one to the other in their normal use.

While the foregoing objects are paramount, other and lesser objects will become manifest as the description proceeds, taken in connection with the appended drawings wherein:

Figure 1 is a plan view of the invention illustrating the dual arrangement of cutting jaws and the shifting mechanism for the selective or collective operation of said jaws.

Figure 2 shows the invention in a side elevational view illustrating the pivotal arrangement of the handles and showing the shifting lever.

Figure 3 fragmentarily shows the invention from one side, a portion of the upper handle being shown removed, on lines 3-3 of Figure 1,

Figure 4 is another fragmentary illustration of the invention showing one of the jaws removed, on lines 4-4 of Figure 1, and showing the stationary cutting blade.

Figure 5 illustrates the left hand jaw in operation, the upper handle being in a raised position.

Figure 6 shows the opposite jaw in operation while the near jaw is inoperative, and

Figure 7 is a perspective illustration of the shifting pin showing the arrangement of the recesses therein.

The invention comprises, primarily, a pair of cutting jaws l0 and II which are oppositely formed and spaced by a stationary cutting blade l2 having a rigid handle l3 secured thereto as by the bolt M, in the manner shown in Figures 2 and 4. The jaws l0 and H are pivotally joined through the blade 4 2 by a bolt or pin l5 and each are provided with sharpened cutting edges it which are preferably arcuate to afford better shearing action on the work. The under cutting surface ii of the blade I2 is also preferably arouate but curved opposite to the edges iii of the jaws l0 and H.

Each jaw I8 and II is substantially conventional in general form but has a shank 18 which curves upwardly from the pivoting segment 49 and extends rearwardly, as in Figure 3, and a slot 20 is provided near its rearmost end having an enlarged aperture 2| at its base. Thus the substantial form of the rearmost end of the shank I8 is that of a hook.

The upper handle 22 is formed with a dual arrangement of rigid arms 23 and 24 by which it is pivoted to the extended arms 25 of the handle 13 by a pin or bolt 26, as illustrated in Figures 2, 5 and 6. The bolt 26 extends through a U-shaped notch 21 in the blade 12-, shown particularly in Figure 4, substantially intermediate the bolt 14 securing the handle l3 and the pivot pin l5 of the handle. 22. The notch 2'1 defines an integral finger which projects upwardly between the shanks ill of the jaws l0 and I! and provides a guide .28 for the latter in operation.

A shifting pin 29, illustrated in detail in Figure '7, is arranged through apertures in the spaced arms 23 and 24 and is adapted to extend through the apertures 2-1 in the slots 20 of the shanks i the jaws l0 and H to provide a rigid connection for the latter with the handle 22. The pin 29 is of such diameter as to accommodate two pairs of opposingly spaced slots or recesses 30 and 3|, each having their flat surfaces at in parallel planes, and each pair having their surfaces a on a diiierent angular plane to the axis of the pin 29, that is, approximating a 30 degree variation, as shown in Figure 7. Such a difierentiation is not intended as a limitation, however, since more or less variation may be desirable.

The flattened portions osccasioned by the paired recesses 30 and 3|, therefore, are designed to enter the slots 20 in the shanks l8 of the jaws 10 or I I, alternately, to render either jaw inoperative, that is. the pin 29 will slide vertically in the slot 20 of the affected jaw without moving the same while the opposite jaw has a rigid connection with the handle 22 through the pin 29 which reposes in the aperture 2| of the slot 20 until the flattened surfaces a of the recesses in this portion of the pin 29 are turned so that they 3 can pass into the slot 20 of the operating jaw.

A lever 32 is rigidly attached to one end of the pin 29 by which the latter is rotated to cause the paired recesses 30 and 3| to register with the respective slots 23, in the manner just described. The lever 32 is preferabl of a flexible material and capable of being flexed so that, in setting the pin 29 in its respective positions to properly align the flattened surfaces a with the slots 20, it may be fixed against voluntary rotation by spaced notches 33 in a segment 34 integral with one of the arms 23 or 24 of the handle 22, as shown in Figures 2, 5 and 6.

For example, in setting the pin 29 so that the left jaw I0 is operated, and the jaw H is stationary, the lever 32 would be arranged in the position shown in Figure 5. The right jaw H is capable of operation when the pin 29 is positioned as shown in Figure 6. When the pin 29 is positioned as illustrated in Figure 2 both of the jaws l0 and I l are operatively connected to the handle 22 and move together as the handles 22 and I3 are manipulated. The frictional tension between the inner surfaces of the jaws l0 and H and the opposite surfaces of the blade l2 are sufficient to retain either jaw in inoperative position when the pin 29 is arranged to permit the operation of the opposite jaw.

The handles l3 and 22 are normally urged apart by a suitable spring 35 arranged therebetween so as to aid in the operation of the jaws l0 and II. A suitable latch (not shown) may be provided for normally holding the handles together when the invention is not in use.

Manifestly, the structure herein shown and described is capable of certain changes and modifications by persons skilled in the art without departing from the spirit and intent of the invention or the scope of the appended claims.

What is claimed is:

1. In sheet metal shears, in combination, a stationary cutting member, a pair of cutting jaws pivotally mounted on opposite sides of said stationary cutting member and each having a sharpened edge for shearing coaction with said stationary cutting member, a handle rigid with said cutting member and a handle having a pivotal connection with said first named handle, and means in the last named handl providing for the selective connection of said handle to said jaws for operation of either of said jaws relative to said stationary cutting member for making a single cut or for simultaneous operation of both said jaws relative to said stationary cutting 4 member for making spaced, parallel cuts simultaneously.

2. In a pair of metal shears, in combination, a stationary cutting blade having a rigidly attached handle, a pair of cutting jaws pivotally and cooperatively arranged on each side of said cutting blade and spaced thereby, each having a sharpened edge for shearing coaction with said stationary blade, a handle having a pivotal connection with said first named handle, capable of operating one or both of said jaws separately or collectively, and adjustable means in said last named handle providing for the selective connection of said last named handle to either of said jaws relative to said stationary member for the operation of either one or both of said jaws relative to said stationary blade for making a single cut or spaced, parallel cuts simultaneously.

3. In sheet metal shears, in combination, a stationary cutting member having a rigid handle, a pair of cutting jaws cooperating with and pivotally connected to opposite sides of said member and each having a sharpened edge, a handle pivotally connected to said stationary member capable of operating one or both of said jaws in a shearing action against said stationary member, and means in said handle for rigidly associating the same with either or both of said jaws for selective or collective operation thereof relative to said stationary member for single or spaced, parallel cuts.

4. In sheet metal shears, a stationary shearing blade having a rigid handle, a pair of jaws pivoted on each side of said blade and each having a sharpened edge for shearing coaction there-' with, a handle capable of operating said jaws pivotally connected to said stationary blade thereagainst, and means in said handle for selectively or collectively rigidly associating the same with either or both of said jaws to move the same in cooperation with said blade.

JOHN M. HART.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,374,819 Byer Apr. 12, 1921 FOREIGN PATENTS Number Country Date 370,795 Germany Mar. 7, 1923 

